Magnetically actuated switching mechanism for well working tool



H. C. EHLERT MAGNETICALLY ACTUATED SWITCHING MECHANISM Aug. 3, 1965 FOR WELL WORKING TOOL 2 Sheets-Sheet 1 Original Filed Jan. 30. 1961 Haw/y C. f/i// z INVENTOR.

BY 4 (M2 Arrofi/vf y Aug. 3, 1965 H. c. EHLERT 3,198,904

MAGNETICALLY ACTUATED SWITCHING MECHANISM FOR WELL WORKING TOOL Original Filed Jan. 30. 1961 2 Sheets-Sheet 2 Harry G f/7/er z INVENTOR nited States Patent This invention relates to well working tools to be run by wire line suspension equipment and operated matically at a preselected subsurface location. The cat application deals more particularly with a novel ric circuit controlling switch mechanism and is a division of Serial No. 85,933, filed January 30, 1961, Patent No. 3,i05,550 disclosing an improved tool 11 can be preset for signaled operation as it traverses any selected one of several subsurface signaling stations each providing :1 distinctively different signal but only one of which will be sensed for work performing response of the tooi in a particular selective setting.

Among the objects of the invention is to provide a circuit controlling switch unit having a pair of contacts of which one is movable toward and away from the other with the pivotal movement of a permanently magnetized lever fulcrumed intermediate its opposite poles and between a pair of spaced apart pole pieces which co-operate with the permanent magnet for attracting the pivoted magnet in one direction of rotation about the fulcrum axis and for causing a reverse rotational movement when the spaced apart pole pieces are subjected to or come within a signaling magnetic field of a polarity for repelling the poles of the magnetized lever.

Other objects and advantages will become apparent during the course of the following specification having reference to the accompanying drawings wherein FIGS. 1A and 1B are companion views showing one embodiment of the tool in vertical section; FIG. 2 is a vertical section the magnetic switch unit with the parts in open circuit rz. 'on; PEG. 3 is a view similar to FIG. 2 but showing the contacts closed; FEGS. 4 and 5 are a vertical section and an elevation respectively as on lines 4-4 and 55 of FIG. 2.

The improved tool, as more fully disclosed in application Serial No. 85,933, now Patent No. 3.l05,550, is for harnessing a signaled release of energy for performing any of various conventional downhole operations at a selected depth in a tubing string. At each of a number of spaced apart locations in the tubing string there will be signaling stations each providing a signal different from the others and to any one of which the tool can be set for response and actuation upon traverse of the selected station.

Each signaling station is illustrated as involving a stack of separate rings retained within a counterbored upper portion of the tubing section 4, the detail arrangement being best seen in FIG. 1B. As they are shown, the lowermost ring 5 is of nonmagnetic material and has embedded in it a series of permanent magnets 6 in the nature of radially disposed bar segments arranged in two vertically spaced apart rows, each containing an annular succession of circularly spaced apart magnets. When these magnets are so arranged and the inner end faces of the magnets in one row are of opposite polarity to the end faces of the magnets in the companion row, ti: "o will be provided between adjoining north and south poles an inwardly protruding magnetic field as a signal to which response can be had by a magneto device which traverses the field. Spaced upwardly above the lowermost magnet carrying ring 5 is a similar ring 5a carrying magnets 6a in circular array and in two vertically spaced apart groups or rows. The two magnet carrying rings preferably are identical subassemblies and they are to be spaced apart different distances at each of the work performing stations. For that purpose, a series of spacer rings, one of which is shown at 7 in FIG. 1B, are interposed between adjacent edges of the rings 5 and 5a.

The wire line suspension tool 8 houses signal responsive operating components and self contained circuitry in which an explosive charge 12 constitutes a source or releasable energy and is to be ignited by a suitable detonator upon completion of the electric circuit by concurrent closing of series connected switches assembled as a part of a set of magneto devices 9-9 which will be described in detail. The magneto devices include normally open switch units in circuit series connection with one another and also with an arming switch 14. Only when the several switches are closed at the same time can actuating current from the battery 15 reach the detonator of the explosive charge for igniting the charge.

Spacer rings ilo-lda of insulating material are interposed between and locate the various components within the tool and the spacers 16a16a diifer in axial dimension and can be disposed interchangeably relative to one another. Interchangeability enables the magneto devices 99 to be spaced apart in different relations by substituting or compounding the spacer rings 16a so that such spacing between the magneto devices can be made to conform with the spacing of the magnetic signaling fields at any of the several signaling stations.

The movable plug of the arming switch 14 is on the lower end of a reciprocatory plunger 17 whose piston head carries a sealing ring 20 and whose upper end is exposed to well pressure at a lateral opening 18 in the wall of the tool 8. .A coil spring 19 biases the plunger upwardly from switch closing position. Downhole well pressures will act on and depress the piston 17 to close the switch 14 and condition the electric circuit for completion when the magneto devices 9-9 traverse magnetic fields to which the devices have been coded. Optionally, the plunger 17 can be located in a set position by locking engagement with it of a set screw 21a threaded in a lateral opening 21 in the tool wall.

Each magneto device 9 is preferably constructed as shown in the detail views FIGS. 2-5. As so disclosed, the unit includes a magnetized rocker lever 22 fulcrumed centrally of its opposite arms on a shaft 23 for rocking in opposite directions of rotation in the space between a pair of annular pole pieces 24 and 25 secured to the top and bottom faces of a pair of transversely spaced apart spacer blocks 26 and 27 of insulating material on opposite sides of the magnetized lever 22 whose axle shaft has its opposite ends mounted in the spacer blocks. The parts are held in assembled relation by means of brass studs 28 which pass through both of the annular rings or pole pieces 24 and 25 and the spacer blocks 26 and 27. The magnetized lever 22 is constituted by a permanent magnet and as illustrated its pivot shaft 23 is mounted closer to the lower pole piece 25 than to the pole piece 24. Accordingly, whenever the swing position of the north pole of the lever is below the horizontal plane of the shaft 23 as viewed in FIG. 2, the lines of force between the poles will provide an attraction tending to rock the lever in a counterclockwise direction with the north pole moving toward the pole piece 25 and the south pole moving toward the upper pole piece 24. A stop to limit such movement is provided by an adjustable screw stud 29 fitted to an insulator sleeve 30 and projected downwardly through the pole piece 24 so that its terminal tip portion is in the upward swing path of the south pole of the pivoted lever. Directly above the north pole of the pivoted ens-s oalever is insulator sleeve 31 extending through the pole piece 24 and adjustably receiving the threaded stud 32 whose tip portion is to be engaged by the north pole as a stop in the path of clockwise movement of the pivoted lever. This tip of the stud 32 provides one of a pair of co-operating switch contacts, the other of which contacts is indicated as a small metal wafer 33 on the upper face of the north pole of the lever 22. A terminal connector is held on the stud 32 for its wired connection is an electric circuit to be controlled. A similar circuit connector terminal 35 is held by a fastening stud 3 6, which passes upwardly through the bottom pole piece 25 and the spacer blocl: 26 for contact at its tip portion with the adjacent mounted end of the supporting shaft of the magnetized rock lever 22. The stud can therefore serve as a current conductor between the magnetized rock lever and the terminal 35 and an additional path for current flow is afforded by a flexible lead wire 37 joined at one end to the connector terminal 35 and at its opposite end to the hub portion of the rock lever 22.

As before indicated, the switch contacts provided by the tip of the stud 32 and the wafer 33 normally are held open by the magnetic attraction between the poles of the permanent magnet comprising the rock lever 22 and the respective spaced apart pole pieces 24 and 25. That attraction can be overcome by imposing on the pole pieces 24 and 25 a magnetic field of different or, in other words, opposite polarity. Thus, as seen in FIG. 3, a magnet 33 is shown positioned beside the unit with its opposite poles arranged to co-operate with the pole pieces 24 and 25. When the south pole of the magnet 38 is uppermost, then the field from the magnet 38 through the pole pieces 25 and 24 will tend to impart a clockwise direction of rotation to the magnetized lever 22,, whose north pole is repelled away from the north pole of the magnet 38 and the pole piece 25, while the south pole of the magnetized lever is attracted toward the pottom pole piece and is at the same time repelled away from the upper pole piece 24 and the south pole of the magnet 38. The imposition of the'field of the magnet 38 in overcoming the holdopen tendency of the permanent magnet comprising the rock lever, is instantaneous and results in a snap action. in like manner, removal of the field of the magnet 38 from influence on the switch unit results in a quick snapopen operation.

The degree of angular movement between open and closed positions can be controlled by relative adjustment of the stop studs 2% and 32 and ordinarily a small range of movement is to be preferred. The projected angularly related broken lines to the ri ht of FIGS. 2 and 3 indicate respectively the inclination from a horizontal plane passing through the pivot axis of the lever in open posi tion and in closed position. At both limits, the north pole in relation to the spaced apart pole pieces is always closer to the bottom pole piece 25. The adjustable stop screws could be set so that the north pole on clockwise rotation would move above the axis and to an extent that the magnetic lines of force of the magnet would then tend to maintain that position. For a subsequent reverse or counterclockwise movement, a magnet such as 33 but with the poles reversed in position to present its north pole uppermost, could then be presented to the pole pieces 24 and 2.5 to restore or rock the permanent magnet lever to its original position. Furthermore, it will be obvious that the electric circuit contacts, if desired, can be transferred from the north pole end of the lever to the south pole end of the lever for co-operation with the screw stud 9 in providing a normally closed electric switch for such situations wherein it is desired to employ an extraneous magnetic field for opening an electric circuit.

What is claimed is:

1. In combination, a magnetic field influenced control unit comprising, a pair of pole pieces spaced apart trans versely of their longitudinal extent, a permanent magnet comprising a rocker lever extended longitudinally in the direction of the longitudinal extent of said pole pieces and fulcrumed intermediate its ends within the space between said pole pieces for swing travel toward and from one of the pole pieces and with its projecting lever arms constituting poles of opposite polarity and whose ines of force pass through the pole pieces and bias lever swing action for normally presenting one of the lever arms to- Ward said one pole piece and which permanent magnet lever responds to the imposition thereon through said pole pieces of opposing lines of force from a magnetic field for a swing action away from said one pole piece, mating contacts controlling cur fl. 7' for lie tion of a worxing means, means mounting one contac for travel with rocker lever travel and other means mounting the other contact in the travel path of said one contact whereby the swing travel of said rocker lever effects the opening and the closing of the contacts and magnetic field means having longitudinally spaced apart poles for field influencing cooperation with said pole pieces, said field means and said control unit being arranged for relative movement into and out of field influencing cooperation.

2. In a circuit controller of the character described, a pair of pole pieces spaced apart transversely of their longitudinal extent, a rocker lever extended longitudinally in the general direction of the longitudinal extent of said pole pieces and comprised of a permanent bar magnet fulcrumed centrally thereof in the space between said pole pieces, a first switch contact on one arm of the lever, 21 second switch contact fixedly mounted in the path of the first contact for circuit closing co-operation therewith and positioned to maintain said one arm of the rocker lever closer at all times to one than the other pole piece, the lines of force of the permanent magnet lever through the pole pieces being in a direction to bias said one arm toward said one pole piece and magnetic field means mounted for cooperation with the pole pieces upon relative traverse the pieces and the arranged to impose on the pole pieces lines of magnetic force of polarity opposite to lines of force of said magnetic lever and thereby bias said one arm away from said one pole piece.

3. In a circuit controller of the character described, a pair of substantially parallel and transversely spaced apart co-operating pole pieces to be exposed on occasion to a co-operating magnetic field, a permanent bar magnet positioned to extend longitudinally in relation to and between the pole pieces for the inclusion of one pole piece within the magnetic field on one side of the magnet and the inclusion of the other pole piece within the magnetic field on the other side of the magnet, means pivotally mounting said magnet centrally thereof for co-operation with the pole pieces in a manner that the magnetic force of the pivotally mounted magnet influences movement of its north pole toward the pole piece near thereto and which influence is countered for repulsion of said north pole in the opposite direction upon exposure of the pole pieces to a magnetic field of opposite polarity, a first circuit closing contact coupled with the pivotally mounted permanent magnet for movement therewith and a second circuit closing contact mounted in the path of the first contact for establishment of contact opening and closing relationships, magnetic field means arranged for controllable exposure thereto of said pole pieces and constituting said field of opposite polarity.

4. In combination, means providing a magnetic field and a device to be actuated thereby, said device including a pair of co-operating pole pieces to be exposed occasionally within said magnetic field for device actuation, a permanent magnet pivotally mounted in the space between said pole pieces for rocking action toward and from one of the pole pieces, a fixed stop engageable with the magnet as a limit of movement thereof away from said one pole piece and positioned to present the magnet north pole closer at all times to said pole piece for attraction normally between the north pole and said one pole piece 5 and which attraction is to be overcome for swinging of said north pole toward the other pole piece when said pole pieces are within said actuating magnetic field, a pair of circuit closing contacts, means mounting one of the contacts of the pivoted magnet for travel therewith and means fixedly positioning the other contact in the path of and for engagement by said first contact for circuit completion in one position of the permanent magnet.

5. In a circuit controlling switch assembly which is responsive to a magnetic field presented thereto, a pair of spaced apart pole pieces, a permanent bar magnet arranged as a lever pivotally mounted centrally thereof and within the space between said pole pieces and closer to one of the pole pieces than the other whereby the north pole 1ever arm is attracted toward the closer pole piece in one swing direction and which attraction will be overcome with reverse lever swing direction when the pole pieces traverse a counteracting magnetic field, means providing such counteracting magnetic field, a switch contact on the lever and a mating switch contact in the path of and to be closed by the lever contact when the swing of the lever is under influence of said magnetic field.

6. In a magnetic switch, a permanent bar magnet fulcrumed on an axis intermediate its ends for rocking action of its oppositely extending arms whose terminal portions constitute north and south poles, a pair of pole pieces substantially co-extensive with the combined length of said arms and positioned on opposite sides of the bar magnet in sandwich-like relation thereto and in planes spaced from said axis transversely to the longitudinal extent of the bar magnet, each pole piece having a pole face in co-operating facing relation to both the terminal south pole of one arm and the terminal north pole of the other arm, means locating said poles and the pole piece faces relative one to another to present one pole closer than the other pole to one of the pole pieces so that the field of said magnet biases the tulcrurned magnet to rock in one direction within the space between the pole pieces, said pole pieces being adapted to be placed on occasion within an outside magnetic field of polarity opposite to that of said permanent magnet and thereby impel rocking of the magnet in the other direction, means providing said outside magnetic field, a first circuit contact fixed relative to said pole pieces and a second contact mounted for movement with said magnet into and out of contact with the first contact.

References Cited by the Examiner UNITED STATES PATENTS 2,671,834 3/54 Kmieck 200-87 2,927,176 3/60 Auld et al 200-87 2,988,916 6/61 Waugh 200-87 3,040,143 6/62 Peay et a1 200-87 3,052,778 9/62 Kathe 200-87 3,121,146 2/64 Pendelton et a1 20087 BERNARD A. GILHEANY, Primary Examiner.

ROBERT K. SCHAEFER, Examiner. 

1. IN COMBINATION, A MAGNETIC FIELD INFLUENCED CONTROL UNIT COMPRISING, A PAIR OF POLE PIECES SPACED APART TRANSVERSELY OF THEIR LONGITUDINAL EXTENT, A PERMANENT MAGNET COMPRISING A ROCKET LEVER EXTENDING LONGITUDINALLY IN THE DIRECTION OF THE LONGITUDINAL EXTENT OF SAID POLE PIECES AND FULCRUMED INTERMEDIATE ITS ENDS WITHIN THE SPACE BETWEEN SAID POLE PIECES FOR SWING TRAVEL TOWARD AND FROM ONE OF THE POLE PIECES AND WITH ITS PROJECTING LEVER ARMS CONSTITUTING POLES OF OPPOSITE POLARITY AND WHOSE LINES OF FORCE PASS THROUGH THE POLE PIECES AND BIAS LEVER SWING ACTION FOR NORMALLY PRESENTING ONE OF THE LEVER ARMS TOWARD SAID ONE POLE PIECE AND WHICH PERMANENT MAGNET LEVER RESPONDS TO THE IMPOSITION THEREON THROUGH SAID POLE PIECES OF OPPOSING LINES OF FORCE FROM A MAGNETIC FIELD FOR A SWING ACTION AWAY FROM SAID ONE POLE PIECE, A PAIR OF MATING CONTACTS CONTROLLING CURRENT FLOW FOR THE ACTUATION OF A WORKING MEANS, MEANS MOUNTING ONE CONTACT FOR TRAVEL WITH ROCKER LEVER TRAVEL AND OTHER MEANS MOUNTING THE OTHER CONTACT IN THE TRAVEL PATH OF SAID ONE CONTACT WHEREBY THE SWING TRAVEL OF SAID ROCKER LEVER EFFECTS THE OPENING AND THE CLOSING OF THE CONTACTS AND MAGNETIC FIELD MEANS HAVING LONGITUDINALLY SPACED APART POLES FOR FIELD INFLUENCING COOPERATION WITH SAID POLE PIECES, SAID FIELD MEANS AND SAID CONTROL UNIT BEING ARRANGED FOR RELATIVE MOVEMENT INTO AND OUT OF FIELD INFLUENCING COOPERATION. 